## Wednesday, 25 February 2015

### "If It Ain't Broke" Scribblings

 Analysing Hit Probabilities
Some time ago I was trying to work out a way of having simpler range brackets, by the looks of my jottings here, as well as the possibility of going over to D20 dice. As it happens it became a thinking out loud on paper exercise into deciding I didn't want to change anything after all.

As it stands, I measure the range, go to the combat chart, get the penetration %, adjust the % for the usual reasons, then roll the dice. As you can guess, very few guns are similar enough to group together in such a chart if you look at their stats closely enough but three categories of weapons did fall into line with each other somewhat: small arms; 13.2mm-47mm; & 75mm-150mm.

Don't get me wrong, I am reasonably happy with the eight range brackets I currently use (Point Blank, Close, Short, Intermediate, Medium, Long, Distant & Extreme). The WRG WW2 rules I used to use felt wrong when either side of a certain range gave a vastly different hit probability. I just wanted to see if I could work out a simplification without increasing the probability steps noticeably or bending the penetration data overmuch by using Point-Blank, Short, Medium, Long and Extreme ranges.

Having not quite ironed out very many of the wrinkles in that idea I then wanted to see if I could devise a way of rolling a handful of D6 for however many attackers were firing within these simplified range brackets, getting back to a long-abandoned group suppressing fire concept I toyed with a few years ago. I am sure it has been done in other rule sets.

Imagining that hit probabilities tail off rapidly towards the end of a trajectory's arc and increase alarmingly at point-blank ranges, I surmised that there might be a largish section in the middle where although, percentages are changing, they are more gradual than at the extremes. Not being a ballistics expert, this was going to be something which was merely required to work in a gaming context, not give very silly results and make everything simpler.

Having decided on PB, S, M, L & X range brackets for the three categories of direct firing weapons and that the M bracket was going to be some kind of norm where, in theory, most of the firing would occur, that left the extremities just needing some adjustment factors and eventually some new adjustments for other combat factors (cover, movement, etc).

All well and good but although the possibly easier to remember range brackets might have resulted in slightly less range table checking there was now going to have to be a roll for penetration, something I did not really want. It could never be factored into the one dice roll, not without, off the top of my head, probably a hit chart for every gun.

Quite an enjoyable bit of noodling about with ideas, nevertheless, if only to conclude I like things how they are.